Viral Haemorrhagic Fevers
Session 29: Viral Haemorrhagic Fevers
Total Session Time: 120 minutes
Pre-requisites
Students Learning Tasks
By the end of this session students are expected to be able to:
signs and symptoms)
Resources Needed:
SESSION OVERVIEW
|Step |Time |Activity/ |Content |
| | |Method | |
|1 |5 minutes |Presentation |Introduction, Learning Tasks |
|2 |25 minutes |Presentation |Introduction to Haemorrhagic |
| | | |Fevers |
|3 |30 minutes |Presentation |Ebola Haemorrhagic Fever |
|4 |15 minutes |Presentation |Marburg Haemorrhagic Fever |
|5 |10 minutes |Presentation |Rift Valley Fevers |
|6 |15 minutes |Presentation |Dengue Haemorrhagic Fever |
|7 |10 minutes |Presentation |Yellow Fever |
|8 |5 minutes |Presentation |Key Points |
|9 |5 minutes |Presentation |Evaluation |
SESSION CONTENTS
STEP 1: Presentation of Session Title and Learning Tasks (5 minutes)
READ or ASK students to read the learning tasks and clarify
ASK students if they have any questions before continuing
STEP 2: Introduction to Haemorrhagic Fevers (25 minutes)
several distinct families of viruses
o They affect many organs
o They damage the blood vessels
o They affect the body's ability to regulate itself
o Some VHFs cause mild disease, but some, like Ebola or Marburg, cause
severe disease and death
Bunyaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae
o They are all RNA viruses, and are all covered, or enveloped, in a
fatty (lipid) coating
o Their survival is dependent on an animal or insect host, called the
natural reservoir
o Humans are not the natural reservoir for any of these viruses
o Humans are infected when they come into contact with infected hosts
the host, humans can transmit the virus to one another
o Human cases or outbreaks of haemorrhagic fevers caused by these
viruses occur sporadically and irregularly; occurrence of outbreaks
cannot be easily predicted
o With a few noteworthy exceptions, there is no cure or established drug
treatment for VHFs
o The viruses are geographically restricted to the areas where their
host species live
mice carry the virus
STEP 3: Ebola Haemorrhagic Fever (30 minutes)
o Ebola is an acute viral infection caused by Ebolavirus, a filovirus
that causes haemorrhage, multiple organ failure, and high mortality
rates
o Primary transmission is from animal to human, through contact with an
infected animal or its product
o Secondary transmission is from person to person through:
ingestion, inhalation and injection of infectious material
o Incubation period is 2 to 20 days
o High grade fever
o Head ache
o Body ache
o Abdominal pain, nausea, vomiting and diarrhoea
o Photophobia, conjunctival injection, jaundice, and lymphadenopathy
o Upper respiratory symptoms (cough, chest pain, pharyngitis)
o Haemorrhagic symptoms (unexplained bleeding)
o CNS symptoms (Delirium, stupor, and coma)
o A maculopapular rash, primarily on the trunk, begins around day 5
o Non-Pharmacological Treatment
be required
o Pharmacological Treatment
o Prevention
patients
STEP 4: Marburg Haemorrhagic Fever (15 minutes)
animals and humans
and a parent type belongs to viral haemorrhagic fevers of Filoviridae
family
o Spread of the virus between humans has occurred in a setting of
close contact, often in a hospital
o Droplets of body fluids, or direct contact with persons, equipment,
or other objects contaminated with infectious blood or tissues are
all highly suspect as sources of disease
o Transmission through infected semen can occur up to seven weeks
after clinical recovery
o Transmission does not occur during the incubation period
o Incubation period is between 3-9 days
o All age groups are susceptible but most case to adults
o Signs and symptoms occur in two phases:
Abdominal pain, Diarrheal, Jaundice, Pancreas inflammation, Severe
weight loss Liver failure, Massive haemorrhage (all orifices), Multi-
organ dysfunction, Delirium, Shock, and Death
o There is no specific treatment, cure, or vaccine for Marburg
Haemorrhagic fever
o Supportive hospital therapy:
o Prevention
STEP 5: Rift Valley Fever (10 minutes)
the bite of infected mosquitoes, transmitting the Rift Valley virus
blood or organs of infected animals through;
o Handling of animal tissue during slaughtering or butchering
o Assisting with animal births, conducting veterinary procedures
o Direct inoculation e.g. via wound from infected knife or through
contact with broken skin or through inhalation of aerosols produced
during the slaughter of an infected animal
o Bite of an infected mosquito
o Acute febrile illness that does not respond to antibiotic or
antimalarial therapy
o Exhaustion, backache, muscle pains, headache (often severe)
o Photophobia
o Nausea/vomiting
o Evidence of bleeding into skin, bleeding from puncture wounds, from
mucous membranes or nose, from gastrointestinal tract and unnatural
bleeding from vagina
o Clinical jaundice
o There is no any established course of treatment of this disease.
o Most of human cases are relatively mild and of short duration so will
not require any specific treatment
o Prevention
STEP 6: Dengue Haemorrhagic Fever (15 minutes)
o Dengue is a mosquito-borne viral infection causing by the dengue fever
virus, whose full life cycle involves the role of mosquito as a
transmitter (or vector) and humans as the main victim and source of
infection
o Dengue does not spread directly from person to person, it is only
spread through the bite of an infected Aedes aegypti mosquito.
o Dengue Febrile Illness (DF):
vomitus, urine, stool; or vaginal bleeding
occur
o Dengue Haemorrhagic Fever (DHF)
o Dengue Shock Syndrome (DSS)
pulse pressure (<20mm Hg)
o No specific treatment is available for Dengue fever
STEP 7: Yellow Fever (10 minutes)
o Yellow fever is an acute mosquito-borne flavivirus infection endemic
in tropical South America and sub-Saharan Africa
o The virus is transmitted to human through a bite of infected Aedes
mosquitoes
o The disease can be life threatening causing haemorrhagic fever and
hepatitis
o Fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue
o No specific anti-viral treatment
o Supportive (symptomatic) therapies are given
o Prevention and control
STEP 8: Key Points (5 minutes)
Arenaviridae, Bunyaviridae, Filoviridae, Flaviviridae, and
Paramyxoviridae
body's ability to regulate itself
STEP 9: Evaluation (5 minutes)
References
Hugo and Russell (2011), Pharmaceutical Microbiology 8th Edition, Willey-
Blackwel publications
Karen C. Carroll et al (2013); Jawetz, Melnick and Adelberg’s Medical
Microbiology 26th Ed. McGraw Hill Co. Inc.
Greenwood et al (2012); Medical Microbiology, 18th edition Churchill
Livingstone
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